Furnace construction



Nov. 22, 1938. I P. WINGERT I 2,137,827

FURNACE CONSTRUCTION Filed April 16 1937 3 Sheqts-Sheet 1 P- WINGERT FURNACE CONSTRUCTION Filed April 16, 1937 3 Sheets-Sheet 2 I I I I I r jr'wemr- 7e; 45

Nov. 22, 1938.

P. WINGERT FURNACE CONSTRUCTION Filed April 16, '19s? 3 Sheets-Sheet 5 w 1 uni PczuZ Patented Nov. 22, 1938 Paul Winger-t, Toledo, Ohio Application April 16, 1937, Serial No. 137,235

18 Claims.

This invention relates to improvements in the combustion chamber construction and arrangement of hot air furnaces, and particularly such devices of the self-feeding or magazine type.

The main objects of this invention are to provide an improved combustion chamber construe-- tion for furnaces; to provide such a device capable of more efllcient operation; to provide a furnace.

whereincombustion can be more positively controlled and is more quickly responsive to control; to provide a furnace in which combustion is localized to a plurality of relatively smallcombustion areas fed from a ,common central fuel supply;

to provide an improved furnace having greater fuel burning capacity per square foot. of grate area; to provide an improved multiple combustion-tube furnace construction; to provide an improved combustion tube construction; and to provide an improved combustion chamber construction. in which fuel deposited on a central grate is burned in laterally disposed individual combustion tubes rather than directly over the central grate portion.

A specific embodiment of this invention is shown in the accompanying drawings in which: I Fig. l is a top plan view of the improved furnace construction showing the furnace casing in section.

Fig. 2 is a side view of the same in elevation as taken on line 2--2 of Fig. 1.

Fig. 3 is a sectional elevation of the same as taken on line 3-3 of Fig. 1.

Fig. 4 is a sectional elevation of the same as taken on line 4-4 of Fig. 1.

Fig. 5 is a fragmentary partially sectioned plan .view as taken on line 55 of Fig. 4. showing the arrangement of the combustion tube. Fig. 6 is a detailed view in elevation of a combustlon tube as viewed from the mouth or com; bustion side, and,

Fig. 7 is a fragmentary sectional view of the combustion tube as taken on line I--'I of Fig. 6. In the form shown in the drawings the improved furnace construction comprises a cylin drical shell 'I having a centrally disposed vertically conical annular grate 2 spaced above an 7 ash pit 3 and having a fire brick lining 4 extend-- ing upwardly from the level of the margin of the grate 2, to define a fuel bowl and fuel reservoir, the fire brick lining being supported on an angle iron member 5 and extending upwardly on the inner wall of the top thereof.

a dome-6.

As shown,

shell is closed by a fuel feeding chute or chamber T shell I to a point adjacent the The top of the leading horizontally from an opening in the furnac'e casing 8 and extending into the upper portion of the shell I or fuel reservoir through an opening provided at the fire brick lining thereof is provided, the chute I being closed on the out- 5 side of the furnace casing by means of a door 9.

In a like manner the with the outside of the casing ash pit 3 communicates 8 by means of a passage III which is closed on the outside of the casing 8 by means of an ash pit door II, the

door I I being provided with the usualdraft opening and damper I2. The conical grate 2 is pivotally supported cenv trally on a vertical shaft I3 carried by a transverse supporting member I4 and a I5 is connected by a link I6 to an arm ing from the margin of so that the grate shaker lever 15 I1 dependthe grate 2,- all arranged 2 can be angularly shifted on the axis of the shaft I3 for the purpose of shaking down ashes formed on the top side of the grate 2. .20

As shown, the furnace casing 8 is spaced well I away from the shell I and is closed at the top so as to completely enclose the furnace shell I and provide a surrounding tering through a cold tion ducts not shown, distributed by supply nected to suitable collars air space in which air en air duct I8, and recirculamay be heated and then ducts, not shown, con- I9 provided at the top portion of the furnace casing 8.

As shown, a pair of combustion tubes or fire tubes 20 are provided on each of opposite sides of the furnace shell I,

which combustion tubes 20 extend laterally outward and-upward relative to the furnace shell as shown in Figs. 1, 2, and 4.

The combustion tubes 20 are hollow elbow-shaped members which communicate with the interior of the furnace shell I through suitable openings 2| provided in the brick lining 4' thereof.

Each combustion tube 20, as shown, with a horizontally disposed portion terminating is formed in 'a relatively narrow vertically elongated mouth opening 22 for communication with the interior of the furnace shell I and theupwardly extending end or vertically disposed portion of the combustion tube terminates in an annular collar portion 23 formed to provide a vertical channel 24 into which the end of a connecting duct or pipe may be 7 seated. Also,

a marginal flange" 25 is provided around the opening 22 of the combustion tube by means of which the combustion tube is secured to the outsideof the shell I by bolts as shown in Fig. 2.

As shown, in Figs. 3

and 4, each combustion tube 20 is disposed'so that the bottom-of the combustion tube mouth 22 will be located adjacent I capacity from which fuel is openings considerable fuel will or in the vicinity of the grate2 and the mouth opening 22 will extend upwardly therefrom. Also, the bottom portion of the combustion tube 20 is formed to slope sharply downward toward the mouth 22 and, at the entrance to the mouth 22, is provided with grate means comprising a plu-- ralityof downwardly projecting fingers or projections 26 which extend into the furnace shell I toward the grate 2. The fingers 'or projections 26 are preferably formed to provide ribs 21 extending into the combustion tube 20 on the inner bottom surface thereof, and provide channel-like grooves or spaces 28 between the ribs 2! on the interior of the combustion tube 20 and spaces or openings 29 between the projecting fingers 26.

Thus, when the furnace is assembled, as shown in Figs. 3 and 4, coal supplied through the said passage 1 to the interior of the shell I will be supported upon the conical grate 2 and if desired the interior of the furnace may be completely filled with fuel as shown in Fig. 4. Thus, the construction provides a magazine of considerable automatically fed gravitationally toward the grate 2.

As shown in Fig. 4, such fuel will fill the mouths of the combustion tubes 20 and because of the vertically elongated formation of the mouth be fed into the body of the combustion tubes. Air for combustion, which is supplied through the ash pit chamber 3 will pass upwardly through the openings 30 in the grate 2 and between the radial fingers 3| provided on the margin of the grate 2. Also, air for combustion will pass upwardly through the combustion tube grate means between the fingers 26 thereof projecting from the bottom portion of the combustion tubes 20 all of which air will pass through the fuel bed and into the combustion tubes 20 as shown by the arrows in Fig. 4. Thus, combustion once started over the grate 2 will tend to confine itself to the immediate vicinity of the mouth openings 22 into the combustion tubes 20 and the major part of combustion will take place in said mouth openings 22.rather than in the central portion of the furnace or directly over the grate 2.

Because of the fact that the draft supplied through the ash pit 3 passes directly through the fuel bed into the several combustion tubes 20 substantially the entire combustion in the furnace will be confined to the combustion tubes, the area directly overthe grate 2 being covered with fresh fuel being fed downwardly into the mouths of the combustiontubes from the upper portions thereof because of the magazine arrangement of the furnace shell above the combustion tubes 20.

The fuel from the magazine is caused to fall or flow into the combustion tubes by shifting the grate 2 back and forth on its pivot thus loosening and shaking down ashes formed above the grate 2 and at the same time tending to shift the fuel bed angularly so that the fuel not directly in front of the mouth openings of the combustion tubes, but at the level thereof, will be brought into position where it can fall into the combustion tube mouths. Also, shifting of the grate 2 with the resultant lateral movement of the grate fingers 3| relative to the combustion tube grate fingers 26 will dislodge and break up any clinkers that might form in the combustion areas at the mouths of the combustion tubes, the fingers 26 and 3| acting as crushing elements.

It will be noted that substantially all of the products of combustion pass upwardly through radiator in its entirety is substantially a the combustion tubes 20. Hence, each pair of combustion tubes is provided with a manifold 32 which collects the products of combustion passing through the respective combustion tubes. The

manifolds 32 lead toward the forward part of the furnace casing and then are turned upwardly and connected into a radiator 33 which. leads toward the rear of the furnace casing where it is joined with a like radiator connected to the manifold for the opposite pair of combustion tubes. Thus, the U-shaped member disposed horizontally in the upper portion of the furnace casing and the legs are extended to and through the front part of the casing 8 where clean-out doors 34 are provided as closures. Finally the radiator 33 is connected into a duct 35 at the rear side of the furnace casing which leads to a stack not shown.

As shown in Figs. 1, 2, and 3, the legs of the radiator 33, at the front side of the furnace casing, are connected by a cross-duct 36 into which a by-pass 31 leading from the fuel feeding chamber 1 is connected. The purpose of the by-pass 31 is to dispose of any coal gases that might collect in the upper portion of the furnace shell I.

The main advantages of this inventionreside in the construction and arrangement of the combustion tubes which provide an increased burning rate for the fuel used and concentrate the burning to a plurality of relatively small combustion areas where combustion control can more easily be had and in which clinkers are less likely to be formed when cheap fuel is burned. Another advantage is in the fact that the greater part of the heat produced by combustion and transmitted to the furnace structure will be concentrated in the bodies of the combustion tubes at the lower' part of the furnace and nearest the cold incoming air that is to be heated, which air will flow over and around the combustion tubes and thus be directly exposed to a greater expanse of metal at the hottest part of the furnace. The result is an increased transfer of heat to the incoming air, lower stack temperatures and a greatly increased overall efiiciency.

Another advantage of the multiple fire tube or combustion tube arrangement is found in the use of tubes of relatively small horizontal area or width, as compared with the periphery of the fuel bowl, so that the portions of greatest heat concentration may be adequately reached by the incoming air to be heated andthus kept relatively cool so that the combustion tubes will not burn out. In prior devices of a similar nature the combustion tubes were relatively wide, horizontally, and the 'deviceswere handicapped by the fact that the combustion tubes would readily overheat and burn out, particularly on the upper surfaces thereof.

Other advantages are found in that the combustion of the fuel is substantially complete leaving little or no unburned portions that may pass with the ashes as waste. Also with the improved furnace construction cheap grades of coal may be completely burned without smoke or soot being produced with the result that a greatly increased economy of operation is obtained.

Although but one specific embodiment of this invention is herein shown and described it will be understood that details of the construction shown may be altered or omitted without dcparting from the spirit of this invention as defined by the following claims.

I claim:

1. A furnace comprising a fuel bowl, a grate at the bottom of said fuel bowl, a plurality of combustion tubes opening into said fuel bowl andextending upwardly and outwardly from adjacent the level of said grate, each of said combustion tubes having a mouth arranged to receive fuel from said fuel bowl, spaced ribs in the mouth of each of said combustion tubes extending on the lower surface thereof toward said grate, and manifold means to receive products i the bottom thereof, a plurality of combustion of combustion from said combustion tubes.

2. A furnace comprising a fuel bowl, a grate at the bottom of said fuel bowl, a plurality of combustion tubes opening into the side wall of said fuel bowl and extending upwardly and out wardly from adjacent the level of said grate, each of said combustion tubes having a mouth arranged to receive fuel from said fuel bowl, grate means in the mouth of each of said combustion tubes, arranged to support the fuel away from the lower margin thereof, and manifold means to receive products of combustion from said combustion tubes.

3. In a furnace having a fuel bowl, a fuel reservoir above said fuel bowl, and a grate at tubes disposed on the outside of said fuel bowl and communicating with. the interior thereof adjacent the level of said grate, each of said combustion tubes having a mouth opening arranged to receive fuel gravitationally thereinto from said fuel bowl and reservoir, means connecting the outer ends of said combustion tubes to create draft therethrough and remove products .of combustion therefrom, and grate means in the mouth of each of said combustion tubes arranged to support the fuel away from the lower margin thereof.

4. In a furnace having a fuel bowl, a fuel reservoir above said fuel bowl, and a grate at the bottom thereof, a plurality of combustion tubes disposed on the outside of said fuel bowl and communicating with the interior thereof adjacent the level of said grate, each of said combustion tubes having -a mouth opening arranged to receive fuel gravitationally thereinto from said fuel bowl and reservoir, means connecting the outer ends of said combustion tubes to create draft therethrough and remove products of combustion therefrom, and grate means projecting toward said fuel bowl from the mouth of each of said combustion tubes arranged to provide draft openings at the lower margin thereof.

5. A furnace comprising a fuel bowl, a fuelreservoir above said fuel bowl, a grate at the bottom of said fuel bowl, a plurality of combustion tubes disposed on the outside of said fuel bowl and communicating with the interior thereof adjacent the margin of said grate, each of said combustion tubes having a mouth open- .ing arranged to receive fuel gravitationally thereinto from said fuel bowl and reservoir, means connecting the outer ends of said combustion tubes to rempve products of combustion r therefrom, and spaced projections extending toward said grate from the mouth of each of said combustion tubes at the lower margin thereof.

6. A furnace comprising a fuel bowl, a fuel reservoir above said fuel bowl, an upwardly projecting conical grate at the bottom of said fuel bowl, means to shift said grate angularlv on its vertical axis, a plurality of combustion tubes disposed on the outside of said fuel bowl and communicating with the interior thereof adjacent the margin of said grate, each of said sloping downwardly to said mouth opening,

combustion tubes having a mouth opening of relatively small horizontal cross section arranged to receive fuel gravitationally thereinto from said fuel bowl and reservoir and having a bottom sloping downwardly toward said grate margin, a plurality of spaced fingers projecting from the bottom of each of said combustion tubes toward said grate, and means connecting the outer ends of said combustion tubes to remove products of combustion therefrom.

7. A furnace comprising a fuel bowl, a fuel reservoir above said fuel bowl, an upwardly projecting conical grate at the bottom of said fuel bowl, means to shift said grate angularly on its vertical axis, a plurality of combustion tubes disposed. on the outside of said fuel bowl and communicating with the interior thereof adjacent the margin of said grate, each of said combustion tubes having a mouth opening of relatively small horizontal cross section arranged to receive fuel gravitationally thereinto from said fuel bowl-and reservoir and having a bottom sloping downwardly toward said grate margin, a plurality of angularly spaced radial fingers on the margin of said grate, a plurality of spaced fingers projecting from the bottom of eachof said combustion tubes toward said grate, and, means connecting the outer ends of said combustion tubes to remove products of combustion therefrom.

8. A furnace comprising a fuel bowl, a fuel reservoir above said fuel bowl, a grate at the bottom of said fuel bowl, a plurality of upwardly turned combustion tubes disposed on the outside of said fuel bowl and communicating with the interior thereof adjacent the margin of said grate through mouth openings arranged to receive fuel gravitationally thereinto from said fuel connecting the outer ends of said combustion tubes to remove products of combustion there: from.

9. A furnace comprising a fuel bowl, a fuel reservoir above said fuel bowl, an annular grate atthe bottom of said. fuel bowl, means to shift said grate angularly on its vertical axis, a plurality of upwardly turned combustion tubes disposed on the outside of said fuel bowl and communicating with the interior thereof adjacent the margin of said grate through mouth openings arranged to receive fuel gravitationally thereinto from said fuel bowl and reservoir, said combustion tubes having their bottoms sloping downwardly toward said grate margin, a plurality of angularly spaced radial fingers on the margin of said grate, a plurality of spaced fingers projecting from the bottom of each of said combustion tubes toward said grate, grate means extending into each of said combustion tubes along the sloping bottoms thereof to support the fuel therefrom, and means connecting the outer ends of said combustion tubes to remove products of combustion therefrom.

10. A combustion device of the class described comprising a hollow elbow-shaped member having a horizontally disposed portion terminating in a vertically elongated mouth opening and ,a vertically disposed portion terminating upwardly in a horizontal opening, said horizontally dissurface and posed portion havingits inner bottom a plurality of spaced fingers extending outwardly from the bottom of said mouth opening.

11. A combustion device of the class described comprising a hollow upwardly extending elbowshaped member having a horizontal portion terminating in a relatively narrow vertically elongated mouthopening, the inner bottom wall of said member sloping downwardly to said mouth fuel bowl and communicating with the interior thereof adjacent the margin of said grate, each of said combustion tubes having a mouth opening arranged to receive fuel gravitationally thereinto from said fuel bowl and reservoir, means connecting the outer ends of said combustion tubes to remove products of combustion therefrom, and spaced ribs in the mouth of each of said combustion tubes extending on the lower surface thereof toward said grate.

13. A furnace comprising a fuel bowl, a fuel reservoir above said fuel how], a grate adjacent the bottom of said fuel bowl, a plurality of combustion tubes disposed on the outside of said fuel bowl and communicating with the interior thereof adjacent the margin of said grate, each of said combustion tubes having amouth opening arranged to receive fuel gravitationally thereinto from said fuel bowl and reservoir, means connect- -ing theouter ends of said combustion tubes to remove products of combustion therefrom, and spaced ribs in the mouth of each of said combustion tubes extending toward said grate and terminating in spaced members projecting from the lower margin of said mouth.

14. A furnace comprising a fuelbowl, an annular grate adjacent the bottom of said fuel bowl, means to shift said grade angularly on its vertical axis, a plurality of combustion tubes disposed on the outside of said fuel bowl and communicating with the interior thereof adjacent the margin of said tion tubes having a grate, each of said combusmouth opening of relatively small horizontal cross section arranged to receive fuel gravitationally thereinto from said fuel bowl and having a bottom sloping downwardly toward said grate margin, a plurality of spaced projections extending from the bottom of each of bustion therefrom.

15. A furnace comprising a fuel bowl, an annular grate at the bottom of said fuel bowl,

means to shift said grate angularly on a vertical axis, a plurality of combustion tubes disposed on the outside of said fuel bowl and communicating with the interior thereofadjacent the margin of said grate, each of said combustion tubes having a mouth opening of relatively small horizontal cross section arranged to receive fuel gravitationally thereinto from said fuel bowl and having a bottom sloping downwardly toward said grate margin, a plurality of annularly spaced radial projections on the margin of said grate, a plurality of spaced projections extending from the bottom of each of said combustion tubes toward said grate, and means connecting the outer ends of said combustion tubes to remove proding a horizontal portion terminating in a mouthopening and a vertically disposed portion terminating in an upwardly opening discharge aperture, said horizontally disposed portion having its inner bottom surface sloping downwardly to said mouth opening, and a plurality of spaced projections extending outwardlyfrom the bottom of said mouth opening.

. 17. A combustion device of the class described comprising a hollow elbow-shaped member having a horizontal portion terminating in a mouth opening and -a vertically disposed portion terminating in an upwardly opening discharge 8138b.

ture, said horizontally disposed portion having its inner'bottom surface sloping downwardly to said mouth opening, and a plurality of spaced ribs on said sloping inner bottom surface extending toward said mouth opening.

18: A combustion device of the class described comprising a hollow elbow-shaped member having a horizontal portion terminating in a mouth opening and a vertically disposed portion terminating in an upwardly opening discharge aperture, said horizontally disposed portion having its inner bottom surface sloping downwardly to said mouth opening, and grate means on said sloping inner bottom surface extending to said mouth 'opening and arranged to provide draft openings at the lower margin thereof. k

a PAUL wmonar. 

